Piston for fluid-pressure engines



May 13, 1930. E, TALBOT 1,758,543

PISTON FORFLUID PRESSURE ENGINES Filed June 12, 192s :s sheets-sheet 1 k K 42 A1| l@ '9 um mi@ .153

May 13, 1930. E, TALBOT vPIsToN FOR FLUID PRESSURE ENGINES Fild June 12, 1928 3 Sheets-Sheet 2 A HH xM-u /f//Mrlff//I 3 3 33 w My 13, 1930. E. TALBOT 1,758,543

PISTON FOR FLUID PRESSURE ENGINES Filed June 12, 1928 5 Sheets-Sheet 5 Patented Mey 13, 193e ERNEST TALBOT, onnowns'rorr, ENGLAND PISTON FOB FLUID-PRESSURE ENGINES Application Bled .Tune 12, 1928, Serial No. 284,826, and in Great Britain November 10, 1927.

This invention relates -to pistons for fluid pressure engines, of the kind in which the head and the skirt are separately constructed and subsequently united by asteners, .the

skirt being of thin cast metal, or wrought metal machined from the solid bar, or formed of drawn tube, or of sheet metal which which is either pressed to shape or bent to a cylindrical `or slightly oval form.

The principal object of the invention is to rovide a simple and light construction which is easy to manufacture and assemble and enable a scraper ring to be fitted to a thin-walled skirt.

F1gu1es 4.-8 each show ternative constructions,

`Figure 9 is a full half section of another construction shown in lower end view by Fi re 10,

ures 11-13 are fragmentary sections showlng' details of the attachment means,

Fi re 14 is a half-section showing the provision of a groove for a scraper ring mdependently of the attachment Bange, and

re 15 shows the employmenti of a Bxing device for the gudgeon pin as-applied to a construction corresponding to Figure 14.

In Figure 1 the skirt 2 is formed in one piece by machining from the solid bar, the exterior being plain, whilst the interior has formed on it an inner radial Bange 3 of a thickness at the root suiiicient to'provide for a rin groove 4 being machined in it, leavin an a equate of the groove. The depth of the Bange beyond the groove is suBicient to accommodate fasteners 5 In the accompanying drawings, which thickness of metal for the wa sv extending through it to secureT the skirt to a jointing face 6 on the cast piston head 7.

The latter may be of any usual construction in which the gudgeon pin bosses 8 are carried integrally or otherwise upon it. Thus,` below the upper portion in which grooves 9 of the ordinary packing rings are provided, the diameter of the head is reduced as at 10 to the desired extent to provide an annular space 11 between-the reduced portion and the se arately formed skirt. Alternatively, as s own by Figure 2, the cast head may be constituted b v a crown 12, a depending Bange 13 ar'ound it containing the packing ring grooves 9, and a'tubular neck 14 extending from the underside of the crown (distinct from the ring-carrying Bange) yand supporting the gudgeon'pin osses 8,or again, the latter may be carried merely by webs extending from the crown and its ring-carryinange. i

he undersides of the lbosses 8 are sufficiently thick for the formation with the face 6 of a concentric shoulder 15 against which the inneredge of the Bangecana ut. Obviously,

if desired, the face 6 and' shoulder 15 may y be on a ringlwhich-ties the two gudgeon pm bosses toget ment for the Ban e 3. It will be evi ent that the construction ]ust described is equally applicable to a skirt formed of cast metal instead of being machined from the solid. y

The skirt shown in Figure 2 is a wrought metal tube and the Bange 16 is formed by rolling, swaging, or Otherwise inwardly pressing the skirt to form a either may be partially Battene as shown to leave a space as at 4 for a ring, or alternatively is completely Battened as in the detail Figure 3, or 1n Figures 14 and 15, when a further groove for a ring, if desired, ma be located above or below the Ban e (see or example Figure 14) Other ,detalls of the connectlon of skirt and head may be as described for Fi re 1.

he skirt shown in Figure '4 is formed of two parts, either of drawn tube or by pressings from sheetmetaL-or by rollin sheet metal into cylindrical form, the a )acont er, giving a more secure engageoove which ends of the two flanged inwardly as at 17 and 18 to form the connecting means and the sides of the ring groove. Between them is inserted a distance ring 19, and this at its outer periphery forms the bottom of' the groove, the fasteners extending through it and through `the anges 17, 18. These parts are accurately registered as already described by means of the shoulder 15.

The distance ring may be provided in one face with one or more annular 'grooves 20 from which extend outwardly any desired number of radial grooves 21. Thus oil collected by a ring placed in the groove 4E is conveyed to the annular groove 20,' and thence it can be delivered to any desired spot lwithin the skirt by aipassage such as 22 extending in the direction of motion of the piston so that the oil is readily dispersed upwardly or downwardly.

By a modification shown in Figure 5, the distance ring between the two flanges can be integrally formed with one or both of the flanges as at 23, that is, either partly on each or wholly on the one flange. In this case the iianges are` folded back upon themselves to form the ring. K-

To suit a thin walled one-piece skirt of wrought metal having a ring groove formed by rolling, the position ofthe groove is such that it will engage in an angleseatin as formed by the faces 6 and concentric shou der 15. A distance ring 24 .is shown in yFigure 6V at the bottom of the groove and may be in two or more segments to enable it to be entered. If the groove is suiiiciently deep the several parts may be retained in position by causing the fasteners 5 to extend through them.

To avoid the necessity for machining the sides of the groove formed for the ring, a

. sure from o die in the form'of a split ring may be provided so as to enter and the outer sides of the groove can then be subjected to presposite sides to close them against the sides o 'the die and form an accurate groove.

If it `is not desired, with a groove thus formed, tol provide the distance rin24, one side of the groove (see Figures 2 an 7) may have formed around it a step 25 adapted to.

form a radial stop for a scraper ring inserted in the groove'. The effect of this step is to give to the groovea contour such as would be if such type is preferred. In Figure 7 the space beyond the step is znot `shown as sufficientlywide for such a ring but serves merely as a collecting groove for lubricant which is then discharged by the assage 26. For such a form of attachment ange 27 it is preferred that the fasteners 5 should not extend through the bottom of the groove but through a parts of the skirt being in the roughly formed 'f `groove from the outside,

clamping plate or ring 28 which at its edge lies over the outside surface of the flange 27 to grip it to the, face 6. Such a clamping plate could be used for the xin means in the construction Figure 2 where t e sides of the groove are flattened into Contact, or for those shown in Figures 6 and 8. In Figures 9 and 10 are shown how the heads of the fasteners 5 may enter cut-away portions in the step 25. Whilst the seating 6 may extend from one gudgeon pin boss to the other, it is preferred to avoid adverse expansion ef'- fectsl (through dissimilar metals of the head and skirt) b leaving a gap between c. tensions of t e seating surface 6.

is gap may be narrow as shown or considerably Wider, and the shoulder 15 now engages the side of the skirt which is formed or machined to suit.

i In Figure 11 a two-part skirt is shown with a step 25 in each flange to' form a ring groove, and the seating 6 has a second concentric shoulder 150.

.The step 2 5' shown both in Figure 2 and F igure 7 may be on the opposite side of the attachment flange as in Figure 12. Figure 13, however, is as in Figures 2 and 7 vbut shows a clamping ring 280 of thicker metal than that at 28, and fits at its edge on the inward face of the step 25. In Figure 12, however, the clamping ring is omitted and the fixing is as 1n Flgure 2, and a shoulder 150 is formed in add1t1on to that at 15.

If it is preferred not to step one side ofthe groove nor to put a distance ring between its sides, then slits 29 (Figure 8) may be made in its base to form tongues 30 which can be bent outwardly. The edges 31 of these tongues thus form stops limitingthe radial movement of a scraper ring mounted in the groove 4, whllst the apertures due to the slits 29 serve for the escape of oil from the groove.

In any of the above constructions, holes 32 or giving access to the gudgeon pin bearings may be provided. Also the upper edge 33 of the skirt and the ring-carrying portion of vthe head may abut asin Figure 2, the edge of the skirt preferably being turned inwards for the purpose, as by spinning or beading, or they may be spaced as shown in Figure 1, or so arranged as to provide for a packing or scraper ring to be located between them (see Figure 9). v

Instead of forming the tongues 30 in the base of the ring groove, they may be formed in one or both of the side walls (see Figure 11). This has the advantage that at the same time apertures 34 are provided in the side walls of the grooves for escape of the lubricant. Tongues on each side of the groove can be in staggered relationshipl with .one another, and preferably with the apertures directly opposite one another.- Thus lthe tongue on one side of the groove would be bpa position a radial atcertain types of' engines i. e., nearer to the -retained by a particular free edge of the skirt see Figures 14:' and 15). Also it allows the udgeon pin to be evice inserted between the e'nd of the pin and the skirt. Thus, if a scraper ring is located at a position between the radial iange and the free edge of the skirt, the gudgeon pin retainer, illustrated at 36, Figure 15, may be adopted, as the resilient loop 37 at its lower end will then clear the inwardly projecting wall of the groove to engage the ledge or inturned bead 42" at the end of the skirt. Alternatively, another constructionl (not illustrated) may be adopted in whichvthe retaining device is secured by the fasteners 5 connecting the head and skirt. In applying either of these two constructions to the present invention, a 'space 38 is provided between the end of the gudgeon pin boss 8 and the inner side of the skirt, and, as the retaining device extends into this space acrossthe end of thegudgeorl pin, it is necessary to* pierce-,as at 39 the radial flange 16 by which the connection of the skirt and head is made, so as to allow for the passage through it of the retaining d oil grooves may device.

In connecting the ularly when the latter is formed of very thin metal, it is preferable to employ' four attachment bolts or screws and to make the contacting area on the face 6 of approximately equal area on each side of the bolt; This reduces the risk of distortion when the bolts are tightened. It will be seen that be provided as required at the positions 40 near the upper edge of the skirt and 411 in the scraper ring groove for 'i the escape of lubricant collected at either of these positions. d

From the foregoing it will be seen that the invention provides a simple, li ht and inexpensively constructed piston aving ample V provision Jfor a scraper ring at any position the whole periphery of sai bove the lower edge of the piston, without sacricing the valuable bearing surface existing between the gudgeon pin VLand the usual packing ringswhere ordinarily space is very limite d What I claim as my invention and desire to secure by Letters Patent of the United States 1s f 1. In a piston, the combination of a cast metal head formed with gudgeon pinbosses,

a concentric shoulder on sald head, a thin metal skirt, aninward ian e formed around skirt, said ange having a concentric shoulder at its inner metal skirt, an inward ange thereon `and bottom,

lhead and skirt, partici 2. In a piston, the combination of a cast metal head yformed with gudgeon pin bosses, o

a concentric shoulder on said head, a thin whereby it is attached to said head, said ilange forming a groove the sides of which thereafter are closely pressed together, and means or\at taching said flange to said head.

3. In a piston, the combination of a cast metal head formed -with gudgeonpin bosses,

a concentric shoulder on said head, a thinA metal skirt, an inward integral flange thereon whereby -it is attached to said head, said flange forming a groove adapted to contain a spring ring and compressing together the sides of the groove on the inner edge of the rin and means for attaching said flange to sai head.

4. In a piston, the combination of a cast metal head formed with gudgeon pin bosses', a concentric shoulder on said head, a thin metal skirt provided with an inturned top an inward annular ring carrying flange formed around the whole. periphery of said skirt, said flange shoulder at its inner edge which registers with that on the head, and means for attaching said flange to said head.

lIn testimony whereof I name to this specification.

, d ERNEST have Signed my TALBOT.,y

having a concentrlc` 

